The Afghan government said Thursday they have released the remaining 400 Taliban prisoners agreed in an exchange, except for "a few" opposed by foreign nations, and expected peace negotiations to start soon.

A drawn-out prisoner swap including the contentious release of hundreds of hardened militants has delayed the start of planned negotiations between the two warring sides, scheduled to take place in Doha. 

"The Islamic Republic of Afghanistan has received our commandos held hostage by Taliban, after which the Gov't released the remaining 400 convicts, except the few for which our partners have reservations," National Security Council spokesman Javid Faisal said on Twitter. "Diplomatic efforts are ongoing. We expect direct talks to start promptly."

Two Taliban officials confirmed the prisoners had been freed and that those opposed by France and Australia were still in government custody. "Australia and France have some considerations about them," one told AFP on condition of anonymity. "The Kabul administration will send them to Qatar where they will be in custody during the intra-Afghan talks."

Their release was opposed by Paris and Canberra because the prisoners were linked to the murder of French and Australian civilians and troops in Afghanistan.

Afghan officials, meanwhile, called for the start of direct talks with the Taliban. "The Afghan government has removed all the obstacles for the direct talks to start," said Najia Anwari, spokeswoman for the State Ministry for Peace Affairs. "The negotiation team of the Islamic republic is now in full preparation to attend the talks,"

Officials said the government-backed negotiating team is heading to Doha later on Wednesday. The date for talks to start is yet to be fixed.